When you upload your Yii website to a Linux server, and you are using yii-rights module you may encounter AuthAssignment table doesn’t exist message.
Table 'DATEBASE_NAME.AuthAssignment' doesn't exist
This is because your tables are in lowercase but in code they are being referred with different capitalization, Linux is case senstive so it treats authassignment and AuthAssignment differently.
In your root/protected/config/main.php specify table names as they are in your database.
'components'=>array( 'authManager'=>array( 'defaultRoles'=>array('guest'), 'class'=>'RDbAuthManager', 'assignmentTable'=>'authassignment', 'itemTable'=>'authitem', 'rightsTable'=>'rights', 'itemChildTable'=>'authitemchild', ),